1. Technical Field
The present disclosure relates to storage systems.
2. Related Art
A storage system typically includes one or more storage devices where information is stored. The storage system may be implemented in accordance with a variety of storage architectures including, but not limited to, a network-attached storage (“NAS”) environment, a storage area network (“SAN”) and a disk assembly directly attached to a client or host computer. The storage devices are typically disk drives organized as a disk array, wherein the term “disk” commonly describes a self-contained rotating magnetic media storage device. The term disk in this context is synonymous with hard disk drive (HDD) or direct access storage device (DASD).
The storage system typically includes a storage operating system that organizes the stored information. The storage operating system may implement a high-level module, for example, a file system, to logically organize information stored on storage volumes as a hierarchical structure of data containers, such as files and logical units. For example, each “on-disk” file may be implemented as set of data structures, i.e., disk blocks, configured to store information, such as the actual data for the file. These data blocks are organized within a volume block number (VBN) space that is maintained by the file system.
In order to improve reliability and to facilitate disaster recovery in the event of a failure within the storage system, it is common to replicate, some or all of the underlying data and/or the file system that organizes that data from a source storage volume associated with a primary storage system or server to one or more remote storage destinations (i.e. secondary storage).
“Snapshot” is one way to replicate a source storage volume. The term “Snapshot” (or “snapshot”) in this context means a persistent point in time (PPT) image of a file system that enables quick recovery of data after data has been corrupted, lost, or altered. Snapshots can be created by copying information at a predetermined point in time to form a consistent image.
A volume based snapshot restore (VBSR) operation may be used to restore a storage volume to a snapshot copy. Typically, a VBSR operation is performed by a storage administrator that has access to the storage devices and is familiar with how a storage volume is being used.
It becomes challenging when the VBSR operation is performed by a host based application that may not be aware of how a storage volume is being utilized, at any given time. For example, the host based application may not be aware that a storage volume may be shared by other host systems; there may be inactive, foreign or inconsistent logical unit numbers (LUNs); or the storage volume may be a root volume.
If a host based application performs the VBSR operation without knowing the characteristics of the storage volume, it may result in unstable conditions within the storage system, including loss of information. Therefore, it is desirable to provide storage volume information to a user before a user performs a VBSR operation.